package breaker

import (
	"git.smesh.lol/moxie/pkg/mxutil"
	"time"
)

func Closed(done chan struct{}) (closed bool) {
	if done == nil {
		return false
	}
	select {
	case <-done:
		return true
	default:
		return false
	}
}

type Deadline struct {
	at   time.Time
	done chan struct{}
}

func After(d time.Duration) (done chan struct{}, dl *Deadline) {
	done = chan struct{}{}
	dl = &Deadline{time.Now().Add(d), done}
	return done, dl
}

func (dl *Deadline) Fire(now time.Time) (fired bool) {
	if dl == nil || dl.done == nil || Closed(dl.done) {
		return false
	}
	if now.Before(dl.at) {
		return false
	}
	close(dl.done)
	return true
}

func (g *Group) Add(done chan struct{}) {
	g.breakers = mxutil.Ensure(g.breakers, 1)
	push(g.breakers, done)
}

func (g *Group) Close() {
	for _, b := range g.breakers {
		if b != nil && !Closed(b) {
			close(b)
		}
	}
	g.breakers = g.breakers[:0]
}

type Group struct {
	breakers []chan struct{}
}